Hi, part of links are broken. I also want to compute separately conductance up-up, down-down, up-down and down-up. I read the threads where up, but I still not sure if i implemented in code correctly with these informations. In my code i use rashba interaction (in code): ---------------------------------------------------------------------------------- def rashba(xi, yi, xj, yj, alpha, t): #d_ij = sitej.pos - sitei.pos x_ij = xj - xi y_ij = yj - yi rashb = 1j * alpha * (sigma_x * y_ij - sigma_y * x_ij) return (rashb - t * sigma_0) ----------------------------------------------------------------------------------- i use norbs=1, because is only electrons And in conductances computations i've implemented (in code): ----------------------------------------------------------------------------------- smat = kwant.smatrix(syst, energy) t = np.matrix(smat.submatrix(1, 0)) #trasmission block from S-matrix tt_mat = np.matmul(t, t.getH()) # t*t_dagger matrix tt = np.trace(np.matmul(t, t.getH())) #trace of t*t_dagger = total transmission counts (up/down) #getting upup Transmission, downdown and downup #up-up t*t_dagger block t11 = np.trace(np.matrix([[tt_mat[i,j] for j in range(int(len(tt_mat)/2))] for i in range(int(len(tt_mat)/2))])) #down-down t*t_dagger block t22 = np.trace(np.matrix([[tt_mat[i + int(len(tt_mat)/2), j + int(len(tt_mat)/2)] for j in range(int(len(tt_mat)/2))] for i in range(int(len(tt_mat)/2))])) #down-up t*t_dagger block t21 = np.trace(np.matrix([[tt_mat[i + int(len(tt_mat)/2), j] for j in range(int(len(tt_mat)/2))] for i in range(int(len(tt_mat)/2))])) ----------------------------------------------------------------------------------- It is completely incorrect compute using these form? I've tryed by smat.transmission((1,0), (0,0)) structure but i got error, and decide to try these aproach above. by information the i got using smat.transmission((1,0), (0,0)) structure: ----------------------------------------------------------------------------------- return self.out_block_coords(lead_out), self.in_block_coords(lead_in) File "C:\Users\Diego\AppData\Roaming\Python\Python39\site-packages\kwant\solvers\common.py", line 854, in in_block_coords self.in_block_offsets[lead_ind][block_ind + 1]) IndexError: index 2 is out of bounds for axis 0 with size 2 ----------------------------------------------------------------------------------- Thanks in advance!